Proton Therapy Now Spans Coast to Coast

A century after the discovery of radium and its potential for treating cancer, a new era in the safe and effective use of radiation therapy has begun for patients at major regional medical centers in the U.S. Advances in computers, medical imaging, and beam precision technology in a clinical environment has spurred the increased accessibility of proton beam therapy for cancer patients.

Nearly 12 years after Loma Linda University Medical Center opened the world's first hospital-based proton center, the Northeast Proton Therapy Center at Massachusetts

General Hospital in Boston, a cooperative program with Harvard University's medical school, opened the nation's second hospital-based proton center. A third center is in development at the M. D. Anderson Cancer Center in Houston, Texas, and a fourth center will open in about a year or two at the Midwest Proton Center in Bloomington, Indiana in partnership with Indiana University.

"After a decade of proving at Loma Linda that proton therapy does what it promises to do, it's apparent to me that proton beam radiation is now a mainstream cancer treatment options," said Leonard Arzt, executive director of the National Association for Proton Therapy, an independent organization that serves as a clearinghouse for patient information. "The public knows it. Patients do their own homework and make informed choices. That's why I've seen a demand for more regional proton centers. People want to cut down on travel time and be closer to home. And, I suspect, that will happen in the next five years."

Hospital-based proton therapy, usually an out-patient procedure for treatment of cancer and other diseases, was first pioneered at the Loma Linda University & Medical Center in 1990. Since then, some 8,000 patients have been treated at the southern California facility following approved by the FDA in 1988. It still remains the world's largest proton treatment center, currently treating 140-150 patients treated daily.

Overall, proton therapy can treat about 20 sites in the body, including pediatric cancers near vital and developing organs. The primary advantage is virtually no side effects, increased dosage control and precision, helping to maintain or improve a patient's quality of life.

Since radium was discovered in 1898, the therapeutic effects of radiation have had many advantages, as well as the possibility of negative side effects. Proton therapy transforms conventional x-ray by depositing virtually all of the energy of the beam at the site of the tumor or disease. In doing so, most serious side-effects commonly associated with x-rays are eliminated, while the power and precision of the proton beam is significantly higher and finer.

The essential advantage of proton therapy lies in accelerated protons' basic physical characteristics. With these charged particles physicians can precisely focus the destructive characteristics of a proton beam in the target volume and greatly reduce the damage given to the normal cells and tissues. This contrasts with X-rays, which are electromagnetic radiation in the high energy or high frequency portion of the electromagnetic spectrum, with very little three-dimensional controllability resulting in greatly reduced ability to avoid unwanted damage to patient's normal tissues. Damage to normal tissues is the cause of patient morbidity in all forms of therapy.

The primary advantage of protons is their precise controllability in three dimensions.

The physician's control of the proton beam allows for enhanced precision in reaching its destination and producing effective, medically proven results in a virtually non-invasive treatment modality.

Protons differ from x-rays which deposit their maximum energy as they enter the body, where it usually is of least benefit to the patient, and decrease in energy deposition as they pass through the body to reach the tumor site where the maximum energy deposition is desired and continue until they exit the body. Energy deposited at any site other than the tumor is the converse of the control displayed by proton therapy; proton will deposit virtually no energy en route to the tumor site, and none beyond the target.

"Proton therapy, often called 'bloodless surgery,' can usually provide greater precision than the surgeon's knife,"said Arzt, The accuracy of the proton beam, along with years of experience by Loma Linda physicians, can now actually exceed the diagnostic ability of current imaging technology. Proton targets cancer with fasting-moving particles that travel close to the speed of light which can be focused precisely on targeted areas of the body. The proton beam has a sharper edge than conventional X-ray therapy, resulting in less spill of radiation into normal tissue.

The new center at Massachusetts General Hospital will replace treatment at the Harvard Cyclotron Laboratory, where physicians have treated more than 9,000 patients since 1961. It will feature a high-power cyclotron, a machine that produces beams that can be moved to treat any site in the body. The center is expected eventually to treat more than 65 patients per day.

Currently, proton therapy effectively treats head, eye, brain and spinal cancers, prostate and rectal cancers, gastrointestinal tumors and certain types of lung cancer. Research and development at Loma Linda University has developed an advanced delivery system using a "scanning" technology which will allow proton's to be used for larger tumor sites, such as breast and more diverse forms of lung cancer. Studies have shown that proton therapy could reduce the medical costs of treating cancer by delivering effective doses of radiation, yet reducing side effects.

More information on proton therapy is available by calling 1-800-PROTONS (776-8667) and visiting Loma Linda's web site at .

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